Irish author John Banville expressed lofty surprise when his dense, defiantly nonlinear novel “The Sea” won the 2005 Booker Prize, claiming in an interview that the award usually goes to “good, middlebrow fiction.” Perhaps aptly for a film about the persistence of memory, those words have come back to haunt him in this good, middlebrow adaptation — which, despite being scripted by Banville himself, sacrifices much of the novel’s structural intricacy for Masterpiece-style emotional accessibility. Lingering literary cachet and a tony ensemble should secure select arthouse bookings for Stephen Brown’s handsome debut feature, but “The Sea” might find sailing smoothest in ancillary.

A short but stately meditation on memory, first (and last) love and the selfishness of grief, merging time planes with disorienting frequency, “The Sea” was a surprise Booker winner, beating Kazuo Ishiguro’s far bigger-selling (yet not dissimilarly themed) “Never Let Me Go” by a single vote. To look at both novels’ glossily melancholy film adaptations, you wouldn’t necessarily guess that one was deemed a more challenging choice. Banville has probably been wise to organize the book’s elastic chronology into a more conventionally defined flashback structure for the screen, though the final effect is inevitably less striking.

The anchoring present-day narrative finds dour art historian Max Morden (Ciaran Hinds) in a quietly morose tailspin following the death of his wife, Anna (Sinead Cusack), from cancer. Against the advice of his adult daughter, Claire (Ruth Bradley), he nurses his grief by withdrawing to the remote Irish seaside village where he spent his summers as a boy, checking indefinitely into an idyllic boarding house, where soft-spoken proprietress Miss Vavasour (Charlotte Rampling) regards him with aloof concern.

Alternating between bouts of increasingly heavy drinking and half-hearted research for a book on Pierre Bonnard, Max ultimately spends most of his time wallowing in two separate spheres of memory: the bleak recent past of his wife’s illness, which she faced with considerably cooler acceptance than he, and the summer of 1955, an end-of-innocence season for the 12-year-old Max (Matthew Dillon).

Shot by d.p. John Conroy in a fluid, golden-filtered style that works in stark contrast to the pic’s otherwise still, somber compositions – effectively suggesting the manipulative qualities of memory – these period sequences detail the working-class boy’s fascination with the Graces, a wealthy family holidaying in what has since become the boarding house. After befriending them on the beach, Max is effectively adopted for the vacation by well-meaning Connie Grace (Natascha McElhone) and her louche husband, Carlos (Rufus Sewell), as a novel plaything for their spoiled, rather unpleasant twins, who run rings around their fragile, distracted young nanny, Rose (Bonnie Wright). While Max is besotted with Connie, it’s chilly, Estella-like female twin Chloe (Missy Keating) who prods the boy’s sexual awakening. More heated desires elsewhere in the family, meanwhile, edge the summer toward a tragic — and for Max, profoundly affecting — close.

Though a final-reel revelation is perhaps too easily telegraphed (in part via Kathy Strachan’s precise costumes), Brown and editor Stephen O’Connell do a deft job of keeping these three narrative strands aloft across a tidy 86 minutes, while rendering their variously unhappy tones pleasingly distinct. Andrew Hewitt’s elegant score, graced with a number of arrestingly mournful solos by young violin virtuoso Hilary Hahn, provides further assistance in this regard.

Afforded the least, but most searing, screen time are Anna’s final days, which economically imply longer-running problems in Max’s marriage. In a uniformly strong cast, a superbly terse Cusack cuts that little bit deeper as a dying woman who understandably has no time for her husband’s hovering pain.